NV-centers in Nanodiamonds: How good they are

TL;DR

This paper introduces a luminescence-based method to determine nanodiamond sizes with NV centers, revises their quantum yield, and discusses their optical properties, highlighting lower efficiency than previously assumed.

Contribution

It presents a novel luminescence intensity method for size estimation and revises the quantum yield and absorption properties of NV centers in nanodiamonds.

Findings

Quantum yield of NV centers can be as low as 5%.

Luminescence intensity correlates with nanodiamond size.

Quantum yield depends on shape and surrounding medium.

Abstract

This paper presents a method for determination of the size distribution for diamond nanocrystals containing luminescent nitrogen-vacancy (NV) centers using the luminescence intensity only. We also revise the basic photo physical properties of NV centers and conclude that the luminescence quantum yield of such centers is significantly smaller than the frequently stated 100\%. The yield can be as low as 5\% for centers embedded in nanocrystals and depends on their shape and the refractive index of the surrounding medium. The paper also addresses the value of the absorption cross-section of NV centers.